I can only suggest that you contact the bigger yachting stores or sailmaking firms for advice. Deep ocean sailors tend to have all that gear for safety on their yachts. The "in the water" equipment such as immersion suits and personal epirbs, water dye markers and harness would be similar whether you are a pilot or sailor. They will be able to kit you out I imagine.
Good luck, hope you never need to use it.
cheers
Gin.